Motor fuel



' gum or discolor or Patented Sept. 8, 1936 UNITED STATES' 2,053,466 PATENT OFFICE ors, by mesne assignments, to Gasoline Antioxidant Company, Wilmington, DeL, a corporation of Delaware 17o Drawing.

22 Claim.

This invention relates to the stabilization of mineral hydrocarbon products. More particularly it relates tmthe utilization of organic compounds as addition substances for thesaforesaid 6 products.

Liquid hydrocarbons as commercially produced possess two apparently distinct phenomena which are especially undesirable. These are, first, a tendency to gum, that is form resinous sub- 10 stances and second to discolor. These phenomena are especially apparent in gasolines produced by modern cracking processes and in motor benzol. Extensive research has been carried out by numerous investigators with the object in view 15 of discovering a means of stabilizing such com- I pounds againstthese phenomena.

One means that has been proposed is the removal of unsaturated cyclic and acyclic bodies from the mineral hydrocarbons. This procedure 20 was not only expensive but in certain instances particularly undesirable because the product so treated had inferior qualities in certain fields, for instance, internal combustion engine fuels.

A second proposal covers the addition to the 25 mineral hydrocarbons of chemical compounds capable of retarding or inhibiting the formation of the aforesaidgums and discoloration. It is to this held that this invention relates.

Apparently it is the belief of certain inves- 30 tigators in this field that gumming and discoloration are directly related. Applicants experience leads them to believe that such is not the case. To support their view it has been found that particular gasolines may be caused to either both depending upon the conditions to which they are subjected. In all probability discoloration is a photo-chemical phenomenon and gumming is a result of a thermal reaction. In any event so far as applicants are 40 aware the prior art does not disclose a chemical compound which will effectively prevent both discoloration and gumming.

Applicants are cognizant of the following patents on this subject:

B. P. 289,347, Somerviile; B. P. 318,521, Lewis; B. P. 319,362, Fischer; B. P. 319,363, Fischer. B. P. 312,774, Jobson; U. S. P. 1,748,507, Brooks.

It will be noted that the first four patents in the above list are directed to gum inhibition and the lasttwo to color stabilization.

This invention has for an'object the inhibition of the formation of insoluble gums and the prevention of discoloration in mineral oils with attendant improvements in the appearance and 55 quality of the hydrocarbon; Another object is to avoid the diiilculties resulting from the formation of the more or less insoluble, sticky or gummy materials, such as cause irregular flow or other detrimental phenomena inthe fuel systems 60 of internal combustion'mgines.

Application September 26, 1930, Serial No. 484,702

Further objects are to make it possible to use as an internal combustion fuel, liquid hydrocarbons such as gasoline, that contain larger amounts of unsaturated compounds.

Still further objects are to produce a product 5 of the character described at a lower cost and one which possesses in certain cases improved anti-knock properties. Other objects will appear hereinafter.

These objects are accomplished by the present invention whereby the amine salts of hydroxyaryl compounds are added to gasoline or oils having similar characteristics. The invention will be readily understood from a consideration of the following examples wherein the parts are given by weight. K 7

One of the tests used for. evaluating the effectiveness of this class of compounds asstabilizers or gum inhibitors is the accelerated oxygentest. In this test twenty-five (25) cc. of motor fuel, cracked gasoline, motor benzol, or the like, treated with 0.001 to 1% of the stabilizing agent are heated at 100 C. in an atmosphere of oxygen for 3 to 6 hours. The gum formed is measured by evap crating the hydrocarbon after the oxygen test from a porcelain dish in the steam oven. The extent of gum formation during the accelerated oxygen test is a measure of the stability and gumming tendency of the fuel during the long time storage. Some of the salts which we have found'to be particularly effective are as follows:

Dianiline salt of hydroquinone H H 11 H r" H' H Anilinesaltoib-naphthol o Di-bntylamine a-naphtholate C4119 0-N/ so H/III\CH' Mono-di-othanolamine salt of catechol w I 0-N-C:H40H

Example I When 0.02% of the dianiline salt of hydroquinone (hydroquinone dianilide) was added to cracked gasoline and 25 cc. were subjected to the accelerated oxygen test for five and one-half hours, the amount of gum formed was 28 mg. Twenty-five cc. of the same gasoline containing no stabilizer run in the same way at the same time gave 232 mg. of gum.

Example II The aniline salt of b-naphthol, added to the extent of 0.005% to cracked gasoline, showed stabilizing action by the accelerated oxygen test. The treated gasoline deposited 305 mg. gum after five and one-half hours, whereas 405 mg. gum were formed in the untreated gasoline.

Example III Cracked gasoline treated with 0.005% di-butylamine a-naphtholate contained 71 mg. gum per 25 cc. after five and one-half hours under the accelerated oxygen test while the same gasoline containing no stabilizer had 405 mg. per 25 cc.

Example IV In a 25 cc. portion of a cracked gasoline, 229 mg. gum were deposited in five and three-fourths hours during an accelerated oxygen test. When 0.02% of the mono-di-ethanolamine salt of catechol was added to the gasoline only 13 mg. gum were formed.

Example V A colorless gasoline, which on exposure to direct sunlight for one hour became cloudy and yellow in color, upon the addition of 0.005% dibutylamine-a-naphtholate remained clear, free from cloud, and developed considerably less color.

The salts used in carrying out this invention have been prepared by mixing equivalent quantitles of specific amine and hydroxy-aryl compounds with or without heating.

In general the invention covers the use of the amine salts resulting from the interaction of all-- phatic and aromatic amines with aromatic hydroxy hydrocarbons. Preferably there are used the salts resulting from the interaction of an amine of Group I with an aryl hydroxy compound of Group 11 following:

Group I Ethylamine Di-ethylamine Ethanolamine Di-ethanolamine Butylamine Di-butylamine Isobutylamine Propylamine Di-allylamine Amylamine Hexylamine Aniline o-Toluidine Xylidine a-Naphthylamine b-Naphthylamine p-Phenylenediamine m-Phenylenediamine m-Toluylenediamine Benzidine o-Anisidine o-Dianisidine 1 z-naphthalene-di-amine Group II Phenol Catechol Hydroquinone Resorcinol Pyrogallol Phloroglucinol o-Cresol p-Cresol Xvlenol (123)-4 Eugenol Guaiacol a-Naphthol b-Naphthol 1 :5 di-hydroxynaphthalene 1:2 di-hydroxynaphthalene 2: 3 di-hydroxynaphthalene Oi these compounds those of Group III following give especially desirable results:

Group III Aniline salt of a-naphthol a-Naphthylamine salt of a-naphthol Di-ethanolamine salt of a-naphthol Mono-di-butylamine salt of catechol Mono-di-butylamine salt of hydroquinone o-Toluidine salt of a-naphthol o-Toluidine salt of catechol Mono-isoamyl-amine salt 01' catechol Iso-amylamine salt of a-naphthol pPhenylenediamine salt of xylenol (1:3) -4 The results obtainable by the compounds oi. Group IV following are so eiIective as to merit special mention:

Group IV Di-butylamine salt of a-naphthol Mono-o-toluidine salt of hydroquinone p-Phenylenediamine salt of xylenol.

It is to "be understood that other isomers and homologues in the classes mentioned above may be used. In certain cases it may be advantageous to use two or more oi. the specific compounds disclosed by this application.

It is not desired to limit the-invention to the concentration oi the stabilizing agents given in the above examples. Use may be made or higher or lower concentrations of any members 01' the class of compounds named and as a result thereof greater or less inhibition of gum formation secured depending upon the specific agent used, the solubility oi the agent, the concentration of the agent, the nature 01' the material treated and the conditions under which the treatment and subsequent storage take place. The preferred actual concentration of the stabilizing agent may vary between the limits of 0.001 to 1.0%. It will be apparent, however, that this range is not given as limiting since lesser or greater amoun may be med in specific instances within the pe oi the invention. In most instances no marked advantage is gained by using more than the maximum amount set out above. In any event the range given appears to be sufiicient for the grades of gasoline and similar oils now on the market.

The incorporation may be made at any desirable stage in the production 01' the substance to be stabilized.

It will be appreciated that the examples outlined above and the specific compounds mentioned are given merely for the purpose otillustrating and not for limiting the invention.

Ithasbeenioundinsomeinstancmthattercowouwosamines will form salts.

tiary aliphatic amines and secondary aromatic As will be obvious from the patents cited above representatives of both the amine group and hydroxy aryl group containing compounds disclosed in this invention have heretofore been used separately in the stabilization of gasoline. It might be assumed that the mere simultaneous use of representatives of each class would accomplish the results of this invention but this has been found not to be the case, for example, alphanaphthol is without effect on the prevention of discoloration of gasoline exposed to sunlight. While it does retard gum formation, it forms an undesirable color. According to this invention the dibutylamine salt of alpha-naphthol has the effect of preventing discoloration and it does not combine with the constituents of the gasoline to form a precipitate.

The stabilizers of this invention possess a heretofore unknown advantage in that they both inhibit gum formation and prevent discoloration. They are miscible with hydrocarbon compounds in all desired proportions, they impart no color to colorless oils and they disperse rapidly when added to the material to be stabilized. Obviously this invention is of great importance in freeing internal combustion engines from the annoyance and improper functioning due to the disadvantages above set out.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments thereof except as defined by the appended claims.

We claim:

1. The process of treating motor fuel mixtures containing cracked gasoline to render them light stable and inhibit gum formation which comprises adding thereto a small amount of an aliphatic-amine salt of a hydroxy-aryl compound.

2. Motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances having incorporated therein an alkylamine salt of a hydroxy-aryl compound in an amount sufficient to retard the formation of the gummy substances.

3. The method of stabilizing a cracked gasoline normally tending to form gummy substances which comprises adding thereto an alkylamine salt of a hydroxy-aryl compound in an amount suflicient to inhibit the formation of the gummy substances.

4. A process for the treatment of cracked hydrocarbon oil of substantially gasoline boiling range to prevent deterioration thereof in respect of gum and color formation and depreciation of antiknock value which comprises adding thereto a relatively small amount of an alkylamine salt of an hydroxy aryl compound. I

5..A motor fuel comprising cracked gasoline normally tending to form gummy substances on storage and having incorporated therein an alkylamine salt of a hydroxy-aryl compound in an amount sumcient to retard the formation of the gummy substances.

6. A process for the treatment of cracked hydrocarbon oil of substantially gasoline boiling range to prevent deterioration thereof in respect of gum and color formation and depreciation of antiknock value which comprises adding thereto a relatively small amount of an alkylamine salt of an hydroxy benzene.

7. The method of stabilizing cracked hydrol vuu carbon spirits normally tending to form gummy substances which comprises incorporating therein an alkylamine salt of a hydroxy benzene compound in an amount sufficient to inhibit;the formation of the gummy substances.

8. The method of stabilizing a motor fuel comprising cracked gasoline normally tending to form gummy substances which comprises incorporating therein an alkylamine salt of a benzene phenol in an amount suiiicient to retard the formation of the gummy substances.

9. A motor fuel comprising unsaturated gum forming hydrocarbons and having incorporated therein an alkylamine salt of a benzene phenol in an amount sufdcient to retard the formation of gum.

10. The method of stabilizing a motor fuel comprising cracked gasoline normally tending to form gummy substances upon storage which comprises incorporating therein an alkylamine salt of a cresol in an amount suificient to retard the formation of the gummy substances.

11. A motor fuel comprising unsaturated gum forming hydrocarbons and having incorporated therein an alkylamine salt of a cresol in an amount suflicient to retard the formation of gum.

12. The method of stabilizing a motor fuel comprising cracked gasoline normally tending to form gummy substances on storage which comprises incorporating therein the butyl amine salt of para-cresol in an amount sufilcient to retard the formation of the gummy substances.

13. The method of stabilizing a motor fuel comprising cracked hydrocarbon spirits normally tending to form gummy substances on storage which comprises incorporating therein an alkylamine salt of a polyhydroxy benzene compound in an amount suflicient to retard the formation of the gummy substances.

14. A process for the treatment of cracked hydrocarbon oil of substantially gasoline boiling range to prevent deterioration therein in respect of gum and color formation and depreciation of antiknock value which comprises adding thereto a relatively small amount of an alkylamine salt of a polyhydroxy benzene.

15. A motor fuel comprising unsaturated gum forming hydrocarbons having incorporated therein an alkylamine salt of a polyhydroxy benzene compound in an amount sufficient to retard the formation of gum.

16. The method of stabilizing a motor fuel comprising cracked hydrocarbons normally tending to form gummy substances on storage which comprises incorporating therein an alkylamine salt of pyrogallol in an amount suflicient to retard the formation of the gummy substances.

17. A motor fuel comprising unsaturated gum forming hydrocarbons and having incorporated therein an alkylamine salt of pyrogallol in amount sumcient to retard the formation of gum.

18. The method of stabilizing a motor fuel comprising cracked hydrocarbons normally tending to form gummy substances on storage which comprisesincorporating therein an amylamine salt of pyrogallol in an amount sufflcient to retard the formation of the gummy substances.

19. The method of stabilizing cracked hydrocarbon spirits normally tending to form gummy substances which comprises incorporating therein a di-alkylamine salt of a hydroxy-aryl compound in an amount sufllcient to inhibit the formation of the gummy substances.

20. A motor fuel comprising cracked gasoline normally tending to form gummy substances on Obdl UH noom storage and having incorporated therein a dialkylamine salt 01' a hydroxy-aryl compound-in an amount sumcient to retard the formation of the gummy substances.

21. A process tor the treatment of cracked hydrocarbon oil of. substantially gasoline boiling range to prevent deterioration thereof in respect of gum and color formation and depreciation of antlknock value which comprises adding thereto a relatively small amount of a dialkylamine salt of alpha naphthol.

aossase :2. mmfuel comprlsini cracked hydrpcar- I bon spirits normally tending to form gummy substances having incorporated therein the dibutylamine salt of alpha naphthol in an amount sum'cient to retard the formation of the gummy 5 substances.

FREDERICK B. DOWNING. HERBERT W. WALKER. 

